http://developer.amazonwebservices.com/connect/entry.jspa?ca... may be of service to help ensure true randomness. It may be necessary to create a voting protocol to prevent malicious mechanical turkers from removing entropy from your boxes, and that should also make it suitably self-policing that you will minimize risk of Apple theft. Considering that Apples are among the most expensive consumer electronics, this would be among any poor student's highest concerns.